Behaviour for handling Discord Gateway events.

Implement this behaviour to handle events from Discord.

Example

defmodule MyBot.Consumer do
  @behaviour EDA.Consumer

  require Logger

  @impl true
  def handle_event({:MESSAGE_CREATE, msg}) do
    case msg["content"] do
      "!ping" ->
        EDA.API.Message.create(msg["channel_id"], "Pong!")

      "!hello" ->
        author = msg["author"]["username"]
        EDA.API.Message.create(msg["channel_id"], "Hello, #{author}!")

      _ ->
        :ignore
    end
  end

  @impl true
  def handle_event({:READY, data}) do
    Logger.info("Bot ready as #{data["user"]["username"]}!")
  end

  @impl true
  def handle_event(_event) do
    :ok
  end
end

Event Format

Events are tuples in the format {event_type, struct} where:

• event_type is an atom like :MESSAGE_CREATE, :GUILD_CREATE, etc.
• struct is a typed event struct (e.g. %EDA.Event.MessageCreate{})

Struct fields are accessible via dot notation (msg.content), atom keys (msg[:content]), or string keys (msg["content"]) thanks to the custom Access implementation — so existing code using string keys still works.

Nested maps (like author, member) remain string-keyed: msg.author["username"] or msg["author"]["username"].

Common Events

• {:READY, %EDA.Event.Ready{}} - Bot has connected and is ready
• {:MESSAGE_CREATE, %EDA.Event.MessageCreate{}} - A message was created
• {:MESSAGE_UPDATE, %EDA.Event.MessageUpdate{}} - A message was edited
• {:MESSAGE_DELETE, %EDA.Event.MessageDelete{}} - A message was deleted
• {:GUILD_CREATE, %EDA.Event.GuildCreate{}} - Bot joined a new guild at runtime
• {:GUILD_AVAILABLE, %EDA.Event.GuildCreate{}} - A guild finished loading during startup
• {:GUILD_DELETE, %EDA.Event.GuildDelete{}} - Bot was removed from a guild
• {:GUILD_UNAVAILABLE, %EDA.Event.GuildDelete{}} - A guild went offline (Discord outage)
• {:SHARD_READY, %EDA.Event.ShardReady{}} - A shard finished loading all its guilds
• {:ALL_SHARDS_READY, %EDA.Event.AllShardsReady{}} - All shards are ready
• {:CHANNEL_CREATE, %EDA.Event.ChannelCreate{}} - A channel was created
• {:INTERACTION_CREATE, %EDA.Event.InteractionCreate{}} - A slash command or component interaction
• {:GATEWAY_CLOSE, %EDA.Event.GatewayClose{}} - A shard disconnected from the gateway
• {:SESSION_RESUMED, %EDA.Event.SessionResumed{}} - A shard resumed its previous session

Unrecognized events are wrapped in %EDA.Event.Raw{} for forward compatibility.

See Discord's documentation for the full list of events.